Thread: Beginner's question: How to redirect shell's standard output into program's stream?

  1. #1
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    Beginner's question: How to redirect shell's standard output into program's stream?

    Hi, this is a beginners question, I appreciate you taking the time to help me out.

    The motivation:
    I want to take the standard output of a shell command (in Red Hat, using tcsh, in my case) and redirect it into my program for processing.

    (Then ideally I would love to take the output of my program and redirect it to yet another command, but this is a second issue.)

    Simple example:

    I naively thought this might work:

    I want to type this on the shell:

    Code:
    $ echo Harry > hello
    and I was expecting this output on my terminal:

    Code:
    $ hello, Harry
    And this would be my simple hello program:

    Code:
    #include <iostream>
    #include <string>
    
    int main() {
      std::string usrInput;
      std::cin >> usrInput;
      std::cout << "hello, " << usrInput << std::endl;
      return 0;
    }
    Thank you very much for your help!

  2. #2
    11DE784A SirPrattlepod's Avatar
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    Last edited by SirPrattlepod; 10-04-2013 at 08:58 PM.

  3. #3
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    Thank you so much. Funny, I was sure I had tested both > and | . Will read more on those operators, thank you!

  4. #4
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    And for other begginers looking at this thread, check this out:
    Code:
    echo Harry > hello
    will write "Harry" to the file hello (and that is when the hello file ceases to be the compiled program and becomes an ordinary text file ;-)

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